Phrasal Verbs: buy down To pay an upfront fee to reduce (an interest rate) over part or all of the term of a loan. buy into To acquire a stake or interest in: bought into a risky real estate venture.Informal To believe in, especially wholeheartedly or uncritically: couldn't buy into that brand of conservatism.buy off To bribe (an official, for example) in order to secure improper cooperation or gain exemption from a regulation or legal consequence. buy out To purchase the entire stock, business rights, or interests of. buy up To purchase all that is available of.